title: Estimation of transmission parameters of a fluoroquinolone-resistant Escherichia coli strain between pigs in experimental conditions.
abstract: Antimicrobial resistance is of primary importance regarding public and animal health issues. Persistence and spread of resistant strains within a population contribute to the maintenance of a reservoir and lead to treatment failure. An experimental trial was carried out to study the horizontal transmission of a fluoroquinolone-resistant Escherichia coli strain from inoculated to naïve pigs. All naïve contact pigs had positive counts of fluoroquinolone-resistant E. coli after only two days of contact. Moreover, re-infections of inoculated pigs caused by newly contaminated animals were suspected. A maximum likelihood method, based on a susceptible-infectious-susceptible (SIS) model, was used to determine the transmission parameters. Two transmission levels were identified depending on the quantity of bacteria shed by infected individuals: (i) low-shedders with bacterial counts of resistant E. coli in the faeces between 5*10(3) and 10(6) CFU/g (βL = 0.41 [0.27; 0.62]), (ii) high shedders with bacterial counts above 10(6) CFU/g (βH = 0.98 [0.59; 1.62]). Hence, transmission between animals could be pivotal in explaining the persistence of resistant bacteria within pig herds.
authors.affiliation: Anses, Fougères laboratory, BP 90203, F-35302 Fougères Cedex, France. mathieu.andraud@ua.ac.be.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Andraud
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rose
authors.forename: Michel
authors.initials: M
authors.lastname: Laurentie
authors.forename: Pascal
authors.initials: P
authors.lastname: Sanders
authors.forename: Aurélie
authors.initials: A
authors.lastname: Le Roux
authors.forename: Roland
authors.initials: R
authors.lastname: Cariolet
authors.forename: Claire
authors.initials: C
authors.lastname: Chauvin
authors.forename: Eric
authors.initials: E
authors.lastname: Jouy
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D024841:Fluoroquinolones / Q000494:pharmacology*; D016013:Likelihood Functions; D013047:Specific Pathogen-Free Organisms; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology / Q000635:transmission*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones